Share this post

Link to post

Share on other sites

I could use a little help here, fellow Anarchists... Just posted some comparisons of the Artemis wing with USA17 and a C Class. I'd appreciate any corrections if I got something wrong, and would love to give credit for two of the pics where I don't know who holds the copyright. http://tinyurl.com/7hqs69l

As I re-read Kimball Livingston's interview with Paul Cayard last Nov, I noticed that the article did say "3 elements, 2 slots." So maybe it is what it looks like: 3 elements, 2 slots.

Share this post

Link to post

Share on other sites

^ I believe KL jumped to that conclusion, when PC never actually said it; and got reemed for it here; probably by Xlot by whose definition an element requires there be a 'real' slot or it's just a 'flap.'. .. X?

I'm still trying to get it too but so far I think in your labels the middle of your 3 elements is a flap off #1, and the trailing ones are separate 'elements' for twist but can be thought of vertically as having one slot, off that flap. ..?

yours

Share this post

Link to post

Share on other sites

^ I believe KL jumped to that conclusion, when PC never actually said it; and got reemed for it here; probably by Xlot by whose definition an element requires there be a 'real' slot or it's just a 'flap.'. .. X?

I'm still trying to get it too but so far I think in your labels the middle of your 3 elements is a flap off #1, and the trailing ones are separate 'elements' for twist but can be thought of vertically as having one slot, off that flap. ..?

yours

I think I have the elements correctly labelled on the Artemis wing. See my annotated pic of the C Class wing. And my annotations of USA 17's wing.

Share this post

Link to post

Share on other sites

I believe that what would have been the slot between the forward and middle elements has been faired over with tape.

The question to me is if it really is a slot, or if it is a much simpler hinge. From the inside the shed shots above, you can see what look like simple hinges on the trailing edge of the fairing/mast/main section.

The control yoke V's are apparently on the middle piece, as seen in the 'man pointing up' photo, which is what has me arguing (for now..) that only the rearmost parts are in fact control- 'slotted.'

I doodled the V's in here, in yellow.

Share this post

Link to post

Share on other sites

The question to me is if it really is a slot, or if it is a much simpler hinge. From the inside the shed shots above, you can see what look like simple hinges on the trailing edge of the fairing/mast/main section.

Share this post

Link to post

Share on other sites

Slowly .. The hinges you highlight should be those of main/rear/slotted flaps, their control yokes being centered there. It is the fact that hinge points are outside flaps that creates the slot, as the flap is deflected.

The hinges of middle flaps are not visible (IIRC blunted mentioned they are double, saloon door type) and what seems to be missing so far is the fairing lip.

Not my theory, but Basiliscus' (what I did was checking main reference texts, and indeed it is so): an element implies circulation, i.e. there must be properly configured air space around it, like a slot but not a plain/sealed hinge.

BTW I was wrong about the spar: it's the lead, D-shaped part like an AC45, a composite skin portion follows.

Share this post

Link to post

Share on other sites

That's beyond my capabilities . But really, look at the C-cat picture and note where the rear flap hinge is (roughly midway through the plain flap) and its control yoke. Then consider that the corresponding hinge on Artemis is one of those you higlighted in yellow in #312 - they are not for plain flaps.

Share this post

Link to post

Share on other sites

flaps have hinges but not slots (an opening designed to induce circulation around the element), elements have hinges (usually) but also slots?

It's good to get the nomenclature clear, but haven't the "things that hang off the back of the wing spar" on the AC45s, been called flaps all along and don't they have a slot that allows circulation between them and the wing spar?

I was initially using the term 'element' here just to indicate three physically distinct 'bits' (but knowing that the 'bits' all had proper marine, aeronautical or multihull descriptors - possibly more than one each!)

It seems we need to establish: a name for each part, whether there is 'flow' around it, where it is hinged, how it is controlled and or limited and whether it twists.

Xlot seems to be suggesting that the 'front slot' may be closed/faired later??

I'd also like to know whether this is all 'string tech' or if hydrualics are used and if so, for which 'bits', how pressurised, how controlled etc.

Share this post

Link to post

Share on other sites

Xlot seems to be suggesting that the 'front slot' may be closed/faired later??

Yes, it's not just C-cats, also ETNZ's SL33s have a seal lip. BTW, as already remarked Artemis are going counter-current in lead element/slotted flap chords ratio

I'd also like to know whether this is all 'string tech' or if hydrualics are used and if so, for which 'bits', how pressurised, how controlled etc.

Top secret?

Indeed - al things considered, the Artemis wing is of interest because it gives an idea of dimensions and sports composite skin. But the real innovation should reside in the 38 hydraulic cylinders PC announced.

Share this post

Link to post

Share on other sites

Should we brake this discussion off into some sort of " wing masturbation " thread ? I'm just sayin .

Good idea, actually. A bit late though.

More importantly, what do you think happens inside 5? There looks to be a 'white' line from the black protruding arm-tip of the yoke, that runs to the right and goes inside of the soft/white middle section of #1.

Share this post

Link to post

Share on other sites

Should we brake this discussion off into some sort of " wing masturbation " thread ? I'm just sayin .

Good idea, actually. A bit late though.

More importantly, what do you think happens inside 5? There looks to be a 'white' line from the black protruding arm-tip of the yoke, that runs to the right and goes inside of the soft/white middle section of #1.

Not sure I'm seeing what you are seeing SR. Is this not just a regular flap control arm as you saw on US17.

Needs a line from inside the wing spar (your 0/1), to either end of this boomerang shaped piece (5), to pull the flap (3), to which it's attached, from side to side. But you know that, so what's different here?

Re your (0); Xlot has changed tack and now says there is no fairing, it's a 'D' shaped spar.

Fap fap

Share this post

Link to post

Share on other sites

The diff from 17's wing is in AR having a hinged 2, right? Am not yet getting the relationship clear between 1, 2, 3 and 5. It could be set up at least two ways (like, does the 5 move directly with 2 or independently, as it controls 3? and what controls 2?) - probably only one geometry makes sense and I'm still behind and scratching my ass.

Share this post

Link to post

Share on other sites

Does the 5 move directly with 2 No or independently, as it controls 3?Yes

What controls 2?See below

2 is idle, and its position is determined by 3 - traditionally, this was done via forks set on 3's leading edge which meshed with 2's trailing edge. At the Newport LAC the Canadians introduced an even simpler system, with (settable) cords in between. If you peer closely at the C-cat picture, you'll see one such cord in the slot just below the red arrow.

Share this post

Link to post

Share on other sites

The diff from 17's wing is in AR having a hinged 2, right? Am not yet getting the relationship clear between 1, 2, 3 and 5. It could be set up at least two ways (like, does the 5 move directly with 2 or independently, as it controls 3? and what controls 2?) - probably only one geometry makes sense and I'm still behind and scratching my ass.

Hey I'm also unclear.

Sure, ARwing #1 has a third, (dare I say it) 'element' (your 3) and therefore also a 2nd 'slot'. (As it appears now)

The experts on the board have suggested two possibilities as far as I can tell and in my ignorance I'd sum them up so:

i/ 3 hinged directly off the back of 0/1 controlled by the levers 5 (which is effectively an extension of the top rib of 3) - with 2 'floating' in between, not directly acted on by anything but constrained by some sort of limiters*

ii/ same as i/ but with 2 being also directly controlled somehow, but as to the hinge arrangements etc, I couldn't guess.

I know jack Griffin is trying to come up with some better explanatory diagrams or annotated photos and also videos.

I would assume though that there is existing material around (C-class for Dummies! or some such) as this is not new - hope it gets posted.

Share this post

Link to post

Share on other sites

Does the 5 move directly with 2 No or independently, as it controls 3?Yes

What controls 2?See below

2 is idle, and its position is determined by 3 - traditionally, this was done via forks set on 3's leading edge which meshed with 2's trailing edge. At the Newport LAC the Canadians introduced an even simpler system, with (settable) cords in between. If you peer closely at the C-cat picture, you'll see one such cord in the slot just below the red arrow.

Share this post

Link to post

Share on other sites

It's a little curious that AR has not yet commented about how scary that thing might be, across any or all aspects. It looks good from a distance but you do have to wonder what the seat of the pants experience might feel like - esp this early.

Share this post

Link to post

Share on other sites

But I misled you by the numbering, that 'slot' you have between 0 and 1 should instead be between 1 and 2 and close to your '2.' 0 and 1 do not articulate, they are in effect one piece with a ball under 0.

Share this post

Link to post

Share on other sites

Am I right in thinking the mast sits under the '1' in Fubaru's sketch? If so, segment '0,1' would pivot as a unit and over a narrower range of motion than the next trailing segment. '2' would be independent of '0-1' and '3' independent of '2', enough to allow for introducing twist. On this reading, '2' has the greatest range of movement, followed by '0-1' and '3.' Wing shape would largely be determined by pivoting '2' to position more of the lifting surface as needed at the moment, with '0-1' introducing the change and '3' refining it, along with aligning the gap beween '2' and '3' to fine-tune the maneuver.

My reading has me rule out a configuration that has '0-1' pivoted to starboard, '2' to port and '3' to starboard. Such an alignment would be self-cancelling. The induced inefficiency would not be complete, ie, relative differences in the areas of the panels or segments would prevent a 'no effect' outcome. All the configurations possible would contribute to a parabolic alignment, with the radii diminishing for each segment and in the order Fubaru has numbered them. So introducing camber would begin by turning '0-1', '2' would be adjusted to compound the change and '3' would be aligned so as to refine the flow from '0-1' and '2'.

I always hoped someone spent astronomical amount on design and hire Airbus, or Boeing to get the best wing. But we have to see what the other teams have in their design sleeve and how it performs..

That why I like the cup... Following it since 1983..

Why do you think that this is their shot at the Cup? This is just the first iteration and I would bet a lot of money that the wing they finally use is quite different from this.

And why would they hire Airbus or Boeing when it is far cheaper to simply hire their staff? There are certainly some people who have worked for those companies within AC teams that i know of. In addition, why do you assume that the best brains for designing these wings are with Boeing and Airbus? There are certainly many others who are as highly qualified, if not more so, than you find at companies like that. BTW, if you want to see how well some Airbus/BAA designers do with sailboat wings, look at the last but one wing on the British Little Americas Cup C Class. Woops!

Share this post

Link to post

Share on other sites

Looking at the photos reminds just how different the AR wing is. For example and aside from AR being double-slotted, the main element on AR is proportionately wider as a part of the whole wing, than what the DZ design has. That chord difference is true when comparing the AR wing to the AC45 wing too.

I always hoped someone spent astronomical amount on design and hire Airbus, or Boeing to get the best wing. But we have to see what the other teams have in their design sleeve and how it performs..

That why I like the cup... Following it since 1983..

Why do you think that this is their shot at the Cup? This is just the first iteration and I would bet a lot of money that the wing they finally use is quite different from this.

And why would they hire Airbus or Boeing when it is far cheaper to simply hire their staff? There are certainly some people who have worked for those companies within AC teams that i know of. In addition, why do you assume that the best brains for designing these wings are with Boeing and Airbus? There are certainly many others who are as highly qualified, if not more so, than you find at companies like that. BTW, if you want to see how well some Airbus/BAA designers do with sailboat wings, look at the last but one wing on the British Little Americas Cup C Class. Woops!

Aerodynamics is most thoroughly studied by aviation-engineering and the approach of design is far more big scale: The development cost of the A380 had grown to €11 billion when the first aircraft was completed.

Engineering-wise it is to be expected that a approach like that eventually will pay.

And about the shot of Artemis: Do you think there will be an multiple amount of wings tested on the AC72's?

One of the reasons Barker was furious on the 100 mln budget is he said that the real winning team will do things like developing multiple wings and the budget will be more in the range of developing an airplane....

Reason why the J's era was ended is when it was exaggerated with Reliance with 144 feet tall build in copper on steel. Ballistic costs ends sportmanship and any normal regatta sailing we saw in the Alinghi-times. Where is the cup going... Is what a lot of people are asking in this forum.

I read on Boat design.net the multiple expressed opinion that the very expensive designed and developed AC-boats are to be expected unpractical for normal yacht design.

And then there is the safety issue of crew being catapulted with 30 + knts in the forestay. Making the cup the most dangerous race in sailing. It was not like that... And AC 33 with 12 knot breeze wasn't exactly what the 34-th cup will look like.

I am not part of any AC team, which is lucky for me otherwise I would be expelled from saying this. Something like the board of directors of Phillip Morris were forced to swear an oath Smoking is not dangerous for your health...

Share this post

Link to post

Share on other sites

It's very easy to suggest that someone knows more about something than the people who are actually doing it and been successful over the years. It's always a mistake to assume that the current best practice is dumb.

Sailplanes, Airplanes, and Sailboats all operate according to aerodynamic theory, but there are significant operating differences that makes each idiosyncratic. For example the requirement that sailboats operate on both tacks is equivalent to requiring equal performance of an airplane upright and inverted. And I mean being able to take off and land inverted, not just be able to fly that way for a few minutes. Further the fact that sailboats operate within the boundary layer mans that there are different wind velocities at different heights of the rig where as sailplanes can count on uniform wind speed along the wingspan.

There are very clever people in these fields, but the problems are different enough to make direct transfer of technology difficult.

I always hoped someone spent astronomical amount on design and hire Airbus, or Boeing to get the best wing. But we have to see what the other teams have in their design sleeve and how it performs..

That why I like the cup... Following it since 1983..

Why do you think that this is their shot at the Cup? This is just the first iteration and I would bet a lot of money that the wing they finally use is quite different from this.

And why would they hire Airbus or Boeing when it is far cheaper to simply hire their staff? There are certainly some people who have worked for those companies within AC teams that i know of. In addition, why do you assume that the best brains for designing these wings are with Boeing and Airbus? There are certainly many others who are as highly qualified, if not more so, than you find at companies like that. BTW, if you want to see how well some Airbus/BAA designers do with sailboat wings, look at the last but one wing on the British Little Americas Cup C Class. Woops!

Aerodynamics is most thoroughly studied by aviation-engineering and the approach of design is far more big scale: The development cost of the A380 had grown to €11 billion when the first aircraft was completed.

Engineering-wise it is to be expected that a approach like that eventually will pay.

And about the shot of Artemis: Do you think there will be an multiple amount of wings tested on the AC72's?

One of the reasons Barker was furious on the 100 mln budget is he said that the real winning team will do things like developing multiple wings and the budget will be more in the range of developing an airplane....

Reason why the J's era was ended is when it was exaggerated with Reliance with 144 feet tall build in copper on steel. Ballistic costs ends sportmanship and any normal regatta sailing we saw in the Alinghi-times. Where is the cup going... Is what a lot of people are asking in this forum.

I read on Boat design.net the multiple expressed opinion that the very expensive designed and developed AC-boats are to be expected unpractical for normal yacht design.

And then there is the safety issue of crew being catapulted with 30 + knts in the forestay. Making the cup the most dangerous race in sailing. It was not like that... And AC 33 with 12 knot breeze wasn't exactly what the 34-th cup will look like.

I am not part of any AC team, which is lucky for me otherwise I would be expelled from saying this. Something like the board of directors of Phillip Morris were forced to swear an oath Smoking is not dangerous for your health...

But I am interested where this will all lead to...

schakel,

I hope we get a chance to share a pint some day - always fun to talk with people who find this AC stuff fascinating. But... I am a big fan of facts and I'm afraid you've got a few facts wrong (see the text in red, above).

Reliance was not a J. She was not built in copper on steel. If you would like some facts about her, see my post in the "AC 35 Boats if RZNYS wins?" (sic) thread, here: Reliance facts.

Ah, those were the days...

Everyone is entitled to his own opinion, but not to his own facts. I tend to give more weight to the opinions of people who get their facts straight. But hey, that's just my personal bias.

Not strictly true as they circle in thermals with a turning radius that is larger but not very much larger than their wingspan, hence the outer wingtip moves significantly faster than the inner and generates more lift. This is in fact an effect of which sailplane pilots need to be aware. They can also sustain inverted flight although inverted landing would be an ill-advised experiment.

My point however was not to disparage wing sail designers but rather to dispute whether airliner designers were best placed to improve wing sail designs.

Share this post

Link to post

Share on other sites

Use this to get the relative chords of the elements 0/1, 2 and 3 at least.....

Yes, a better mechanical sketchup would be great.

It could also be interesting to compare AR's wing chord proportions to the AC45 wing, and then consider the differences.

And this may be difficult but in one or more of the screen shots I posted earlier from CNN and/or ACU 30 intentionally for the purpose, it may be possible to determine the cross section shape of the main with reasonable accuracy; and to then compare that section to the AC45 cross section, diagrams of which we do have somewhere. Which is proportionately 'thicker'? And which has its thickest point more forward than back?

Share this post

Link to post

Share on other sites

I'm not convinced that there aren't two slots from top to bottom. I see six different sections from top to bottom. In post #247 (picture below), there are slots between the #1, #2, and #3 elements (two slots) visible on all but the bottom section of the wing which only shows a slot between the #2 and #3 element. However, in the construction photos (post #301) shows the trailing edge of bottom of the #1 element to be tapered to a point instead of having a recces that the #2 element rotates in as depicted in post #333. This suggests that it isn't a plain flap without a slot.

My suggestion is that the #2 element at the top and bottom sections can be controlled independently of the other #2 elements. Not all pictures show the slot between the #1 and #2 elements because the angles of the #2 and the camera are not lined up to show the slot.

Share this post

Link to post

Share on other sites

Aerodynamics is most thoroughly studied by aviation-engineering and the approach of design is far more big scale: The development cost of the A380 had grown to €11 billion when the first aircraft was completed.

Engineering-wise it is to be expected that a approach like that eventually will pay.

While Steve has explained that the problems are different and that direct transfer of knowledge/ideas doesn't work, one of the Artemis guys did work on the design and development of the A380 wing. However, boats was always his passion and he left BEA to sail full time and later, work for AC teams. And the development costs of the A380 wing were only a small part of the 11 billion.

And about the shot of Artemis: Do you think there will be an multiple amount of wings tested on the AC72's?

Yes, there is a limit but I elieve that for the top teams, only the last 2 will be the same (they will need a spare). Other than that, we should see teams try some very different ideas within their allotted number of wings.

Share this post

Link to post

Share on other sites

From what I can see it is more likely to be something like this, using a drooping leading edge to effectively camber the major leading element to get higher lift coefficients.

If they can twist the leading edge element they can introduce some aerodynamic twist into the rig as well.

It could be. That would explain why the leading edge is vertical and the flap hinges are not vertical. If it is, I think the front section is the structural part because that is where the rigging looks like it attaches. The CNN video of the wing hanging certainly look like there are two parts to the front element and that the front part is joined to the big control arm at the base of the wing.

Share this post

Link to post

Share on other sites

I've been drawing the double slot configuration of what the pictures may appear to be. Not sure about the hinge pivot placement.

That's more like it -great

It is really difficult to see in any of the shots so far but my impression is that the 'rear' flaps 3, are hinged directly off the back of the main spar 0/1. We have seen the hinge points clearly especially in the shots of spar horizontal (in the factory and in the packaging).

I can't imagine an indirect linkage through the light looking 'intermediate' flap 2, as you have drawn it would be up to the job.

Share this post

Link to post

Share on other sites

I've been drawing the double slot configuration of what the pictures may appear to be. Not sure about the hinge pivot placement.

That's a lot better - Thanks.

It's difficult to tell from the photos but I'm reasonably convinced that the 'rear' flaps (3) are hinged directly off the main wing spar (0/1). (We have seen the hinge points in the shots of the spar when it was horizontal in the factory and also coming out the door packaged)

It's hard to imagine the indirect linkage through the flimsy looking 'intermediate' flaps (2), as you have drawn it, being robust enough.

TH: We’ve had an AC72 wing on a trimaran and it’s unbelievably impressive from start from finish. From watching the shore team execute getting the wing in the boat to getting the boat off the mooring to going out sailing. The whole thing is on a magnitude of something I don’t think anybody really thought all the way through when the thing was being written. It’s going to be exciting times ahead of us. All the teams are in for an eye opening experience. It’s been awesome to be out sailing with an element of the AC72 and to be the first ones doing it.

Share this post

Link to post

Share on other sites

TH: We've had an AC72 wing on a trimaran and it's unbelievably impressive from start from finish. From watching the shore team execute getting the wing in the boat to getting the boat off the mooring to going out sailing. The whole thing is on a magnitude of something I don't think anybody really thought all the way through when the thing was being written. It's going to be exciting times ahead of us. All the teams are in for an eye opening experience. It's been awesome to be out sailing with an element of the AC72 and to be the first ones doing it.

Really fascinating interview, particularly hearing TH's awe of the wing and how it is going to relate to SFO:

...

Where the advantages are, I’m not sure we know enough yet. Obviously understanding the wing and getting it to be as efficient but simplistic - you can probably make something very complicated but getting it through the race course could be another thing. Obviously the dagger board is going to be a big key to the performance of the boat because ultimately in the high speed bearaways, the dagger board will keep the bow up and out of the water. But looking at it from the design side, the wing was the obvious place to start for us.

The racecourse prescribed for the 72s? Having now been in the 45, what are your fears, what are you anticipating once you hit that start line?

TH: It’ll be interesting to see how the teams gear their boat. When you look at the first reach across from somewhere underneath the Golden Gate, towards the Presidio and Crissy Field, that’s the first area of worry because depending on the angle that they set you, the boat’s very easily going to go 40 knots. When you watch how we race the 45s - you have a quick deploy and maybe 45 seconds to a boundary, having a boat that can handle that type of deploys that we do in the AC45s, there’s the next question mark that we continue to debate. Will we be able to deploy on this boat much in the same manner that we do on the 45?

While that’s happening, the boat is screaming along between 35 and 40 knots of boatspeed, there’s going to be plenty to digest. I’d say that the next challenge for the teams are the boats that jibe and speed build well out of each manouevre. Down the run there’s a lot of gain and loss in that.

Conversely, the boat that can get around the bottom mark efficiently with the boat handling element and settle into an upwind mode - because we have the restrictions of the boundaries - understanding the long tack out of the bottom and maximizing the amount of runway that you can give the boat and also trying to do the beat with less tacks. When you consider that the boat will go 20 knots upwind and in the tacks it’ll probably drop down to 6 or 7 knots, there’s a pretty big loss in performance so the team that figures out those problems will probably be the team that is successful.

....

Share this post

Link to post

Share on other sites

.... how do you derive your boat speed? Through your boat handling, through the boat’s acceleration out of tacks and jibes - those are ways that you can be faster than your competition. Your competition, if you did a ten mile leg, might be four or five minutes quicker but they can never achieve that boat speed on this course, so I think the challenge that all the teams face - I know certainly we face - how do we maximize all the great talent of Juan K and our design team but also keep it in a perspective that is reasonable because you run into a boundary every 90 seconds. I think it’ll be an experience that none of us have ever seen - just looking at the sheer size and the power that the wing on the trimaran has created.

...

Kind of supports what many of us have claimed, that a team like ET, even using the stock plans and a shoe-string budget, may have the best chance of being competitive than any other time in the AC's history. Those members of the French team have more experience than anyone dealing with incredibly challenging maneuvers, with big boats, in big conditions. These teams focusing on Finn sailors, I believe, may be REALLY missing the point.

Share this post

Link to post

Share on other sites

TH: We've had an AC72 wing on a trimaran and it's unbelievably impressive from start from finish. From watching the shore team execute getting the wing in the boat to getting the boat off the mooring to going out sailing. The whole thing is on a magnitude of something I don't think anybody really thought all the way through when the thing was being written. It's going to be exciting times ahead of us. All the teams are in for an eye opening experience. It's been awesome to be out sailing with an element of the AC72 and to be the first ones doing it.

How many of you think Artemis has secured an advantage from sticking their wing on a tri?

Will these early tests give them an advantage later?

Share this post

Link to post

Share on other sites

Kind of supports what many of us have claimed, that a team like ET, even using the stock plans and a shoe-string budget, may have the best chance of being competitive than any other time in the AC's history. Those members of the French team have more experience than anyone dealing with incredibly challenging maneuvers, with big boats, in big conditions. These teams focusing on Finn sailors, I believe, may be REALLY missing the point.

Those guys probably go 100 miles between maneuvers. So, they might not be as good at accelerating quickly.

Share this post

Link to post

Share on other sites

Kind of supports what many of us have claimed, that a team like ET, even using the stock plans and a shoe-string budget, may have the best chance of being competitive than any other time in the AC's history. Those members of the French team have more experience than anyone dealing with incredibly challenging maneuvers, with big boats, in big conditions. These teams focusing on Finn sailors, I believe, may be REALLY missing the point.

Those guys probably go 100 miles between maneuvers. So, they might not be as good at accelerating quickly.

Of course, but at the same time, they have been making maneuvers on BIG boats, with BIG rigs, going REALLY fast in brutal environment, likely hundreds of times per year. I don't see that being the case with a bunch of Finn or 49er sailors. That is not a hit on them, just pointing out what these guys bring to the table for big boats, going really fast, with big rigs, in SFO.

Share on other sites

TH: We've had an AC72 wing on a trimaran and it's unbelievably impressive from start from finish. From watching the shore team execute getting the wing in the boat to getting the boat off the mooring to going out sailing. The whole thing is on a magnitude of something I don't think anybody really thought all the way through when the thing was being written. It's going to be exciting times ahead of us. All the teams are in for an eye opening experience. It's been awesome to be out sailing with an element of the AC72 and to be the first ones doing it.

How many of you think Artemis has secured an advantage from sticking their wing on a tri?

Will these early tests give them an advantage later?

If it was larry would have done it already .

Share this post

Link to post

Share on other sites

I had the rear flap arm drawn too short . I placed it' s pivot about at the rear of the main. The middle flap floats and has stop guides to control how much gap is allowed. Early on I posted a picture of a dirt boat with a double slot. He arraigned his about like my second drawing with the stops.

I've been drawing the double slot configuration of what the pictures may appear to be. Not sure about the hinge pivot placement.

That's a lot better - Thanks.

It's difficult to tell from the photos but I'm reasonably convinced that the 'rear' flaps (3) are hinged directly off the main wing spar (0/1). (We have seen the hinge points in the shots of the spar when it was horizontal in the factory and also coming out the door packaged)

It's hard to imagine the indirect linkage through the flimsy looking 'intermediate' flaps (2), as you have drawn it, being robust enough.

Share this post

Link to post

Share on other sites

That looks pretty close to my untrained eye. Xlot posted earlier in the thread with the various fork and string style limiters that have been used in the past to control the rotation of the intermediate flap.

Look again at those spar photos from the factory and you might move the hinge point back a touch from the spar, And open the 2nd slot a little more. (But only if you are revising it anyway)

Great job and a good basis for future discussion. Need to agree on the best lables now. There will be what, another 10 iterations maybe of this basic set up to discuss before the Match?

Share this post

Link to post

Share on other sites

Have a look at triangular brackets on hinges, they are flush with the wing profile (they don't stick out in the full wing picture). This should mean the lead element's trailing edge is not sharp - as would be the case with a slotted flap.

Share this post

Link to post

Share on other sites

Kind of supports what many of us have claimed, that a team like ET, even using the stock plans and a shoe-string budget, may have the best chance of being competitive than any other time in the AC's history. Those members of the French team have more experience than anyone dealing with incredibly challenging maneuvers, with big boats, in big conditions. These teams focusing on Finn sailors, I believe, may be REALLY missing the point.

Those guys probably go 100 miles between maneuvers. So, they might not be as good at accelerating quickly.

Share this post

Link to post

Share on other sites

.... how do you derive your boat speed? Through your boat handling, through the boat’s acceleration out of tacks and jibes - those are ways that you can be faster than your competition. Your competition, if you did a ten mile leg, might be four or five minutes quicker but they can never achieve that boat speed on this course, so I think the challenge that all the teams face - I know certainly we face - how do we maximize all the great talent of Juan K and our design team but also keep it in a perspective that is reasonable because you run into a boundary every 90 seconds. I think it’ll be an experience that none of us have ever seen - just looking at the sheer size and the power that the wing on the trimaran has created.

...

Kind of supports what many of us have claimed, that a team like ET, even using the stock plans and a shoe-string budget, may have the best chance of being competitive than any other time in the AC's history. Those members of the French team have more experience than anyone dealing with incredibly challenging maneuvers, with big boats, in big conditions. These teams focusing on Finn sailors, I believe, may be REALLY missing the point.

I think you are missing the point, although we might agree on the Finn sailors. You are assuming that the gains in tacks and gybes will be made from crew work. It will be partly crew work, but it will be all about how they play the wing and what they can do with it. The fastest tacking/gybing boats will be the ones that find a way to "mode" the wing to tack/gybe, in order to reduce drag and therefore not decelerate as much. There is only so much that basic crew work can achieve and given the time available, you have to assume that the top teams will become equally skilled at the moves. However, if your rig controls are such as to be able to change the rig for the manouver, and the crew are good at doing it, you will gain huge amounts. In the same way. a boat that sails higher but slightly slower might need less tacks and therefore teams need to understand what the gains/losses are from this aspect.

For this reason, Artemis having a wing on the water has to give them the best chance of developing things.

If it was larry would have done it already .

Please can you explain why OR and LE have the sole right to good ideas and getting one overv the opposition? Yours is a truly rediculous statement.